简单的TCP连接（send/recv使用的sockfd）

Linux C Socket TCP编程介绍及实例

server.c

#include<sys/types.h>

#include<sys/socket.h>

#include<stdio.h>

#include<netinet/in.h>

#include<arpa/inet.h>

#include<unistd.h>

#include<string.h>

#include<stdlib.h>

#include<fcntl.h>

#include<sys/shm.h>
#define MYPORT  8887

#define QUEUE   20

#define BUFFER_SIZE 1024
int main()

{

 int server_sockfd = socket(AF_INET,SOCK_STREAM,0);

 struct sockaddr_in server_sockaddr;

 server_sockaddr.sin_family = AF_INET;

 server_sockaddr.sin_port = htons(MYPORT);

 server_sockaddr.sin_addr.s_addr = htonl(INADDR_ANY);

if(bind(server_sockfd,(struct sockaddr*)&server_sockaddr,sizeof(server_sockaddr)) == -1)

{

  perror("bind");

  exit(1);

}
if(listen(server_sockfd,QUEUE) == -1)

{

  perror("listen");

  exit(1);

}
printf("waiting for connection\n");
struct sockaddr_in client_sockaddr;

socklen_t length = sizeof(client_sockaddr);

char buffer[BUFFER_SIZE];

int newFd = accept(server_sockfd,(struct sockaddr*)&client_sockaddr,&length);

if(newFd == -1)

{

  perror("connect");

  exit(1);
}

printf("connect successfully\n");
while(1)

{

  memset(buffer,0,sizeof(buffer));

  int len = recv(newFd,buffer,sizeof(buffer),0);

  if(strcmp(buffer,"exit\n") == 0 || len <= 0)

  break;

  printf("data from client: %s\n",buffer);

  send(newFd,buffer,len,0);

  printf("data send to client: %s\n",buffer);

}

  close(newFd);

  close(server_sockfd);

  return 0;

}

client.c

#include <sys/types.h>

#include <sys/socket.h>

#include <stdio.h>

#include <netinet/in.h>

#include <arpa/inet.h>

#include <unistd.h>

#include <string.h>

#include <stdlib.h>

#include <fcntl.h>

#include <sys/shm.h>
#define MYPORT  8887

#define BUFFER_SIZE 1024
char *SERVER_IP = "127.0.0.1";
int main()

{

  struct sockaddr_in client_sockaddr;

  int client_sockfd = socket(AF_INET,SOCK_STREAM,0);

  client_sockaddr.sin_family = AF_INET;

  client_sockaddr.sin_port = htons(MYPORT);

  client_sockaddr.sin_addr.s_addr = inet_addr(SERVER_IP);

int coFd = connect(client_sockfd,(struct sockaddr*)&client_sockaddr,sizeof(client_sockaddr));

  if(coFd == -1)

  {

    perror("connect");

    exit(1);

  }

  printf("connect successfully\n");
  char recvBuf[BUFFER_SIZE];

  char sendBuf[BUFFER_SIZE];
  while(fgets(sendBuf,sizeof(sendBuf),stdin) != NULL)

 {

    send(client_sockfd,sendBuf,strlen(sendBuf),0);

   if(strcmp(sendBuf,"exit\n") == 0)

    break;

   printf("send data to server: %s",sendBuf);

   recv(client_sockfd,recvBuf,strlen(recvBuf),0);

   printf("receive data from server: %s",recvBuf);

   memset(recvBuf,0,sizeof(recvBuf));

   memset(sendBuf,0,sizeof(sendBuf));

 }

close(client_sockfd);

return 0;

}

send recv的s选项：
对server.c 使用accept的返回值
对client.c使用原始的client_sockfd
如果client.c使用connect的返回值
client.c 接受的值是乱码，server.c不显示接收值和返回值